This trainer has been downloaded by over 6,000 members so far and yours is the only complaint of this nature. Something on your end is either stuck or interfering with the trainer. Trainer is operating fine.

sticking keys has happened to me too but as things stand, big mans right, its the keyboard on our ends hanging up on a key, try pressing all the cheat options so the keyboard can sort itself out with the new input rather than enabling and then disabling the same cheat over and over.

that being said, latest patch and latest trainer still has some issues, particularly with invulnerability. crashing on loading a new area is pretty common. maybe something like whats been done with the Deus Ex Human Revolution trainer would fit nicely, disabling the cheat upon entering a new area. but meh... I don't know specifically if thats the problem or not, all I can say is that gameplay is a lot more crash free without using the infinite health option of this trainer.